Whey media, containing 2% (w/v) whey powder, 1% (w/v) glucose, and 0.5% (w/v) yeast extract, were fermented with nine Lactobacillus strains to produce angiotensin I-converting enzyme (ACE) inhibitory peptides. Lb. brevis, Lb. helveticus, and Lb. paracasei were most effective in producing whey hydrolysates that contained potent ACE inhibitors, with the inhibition rate ranging from 93.3 +/- 0.3 to 100%. The hydrolysates of three Lactobacillus strains were partially purified by dialysis (6,000--8,000 Da cut-off) to remove larger molecules, and subsequently subjected to RP-HPLC, equipped with a Delta Pak C18 column. Each chromatogram displayed at least three distinct peaks at the hydrophobic region of the elution profile. Altogether fourteen peaks were purified and assayed for ACE inhibitory activity. All peaks except one exhibited ACE inhibitory activities, with IC50 ranging from 5.3 +/- 0.1 to 2637.8 +/- 366.9mug/ml. Three of these peaks contained pentapeptides, which consisted of mostly hydrophobic or aromatic amino acids at the C-terminal.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.32746 |
| Date | January 2001 |
| Creators | Ahn, Jae-Eun. |
| Contributors | Lee, Byong H. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Food Science and Agricultural Chemistry.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001872224, proquestno: MQ78818, Theses scanned by UMI/ProQuest. |
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